The present invention relates to a pigment paste for concrete, a method for making the same, and a method for using the pigment paste with concrete. More particularly, the invention relates to a pigment paste that alters the appearance of concrete such that, after the concrete sets, it resembles natural stone. The finished concrete structure may be suitable for the construction of architectural panels, flooring, paving, countertops, tiles, retaining walls, furniture, columns, and sound barriers.
Concrete generally has four components: a cement, a course aggregate of one or more rocks or minerals (e.g., granite, basalt, sandstone, etc.), a fine aggregate of sand, and water. Upon adding water to the cement and aggregate mixture, an exothermic reaction is induced which, after time, hardens the concrete. It is desirable to use concrete because it is the only major building material that can be delivered to a job site in a soft state. This unique quality makes concrete a desirable building material because it can be molded to virtually any form or shape. However, while concrete is a durable and less expensive building material than other materials, such as natural stone (e.g., marble, granite, sandstone, bluestone, etc.), concrete easily stains and is generally considered less attractive.
Alternatively, because granite and marble possess the qualities of versatility coupled with strength and durability, both granite and marble are used for countless applications around the home. Granite is a crystalline, granular rock consisting of colored feldspar, white quartz, mica, and ferromagnesian minerals. These minerals vary in composition and hardness. Marble, although similar in composition, is not as hard as granite. Granite and marble are natural stones each containing a high amount of quartz which has cooled from a molten state inside the earth over a long period of time under immense pressure. Because it is formed naturally, each piece of granite and marble also possess a unique design. Granite is one of the hardest building materials, as demonstrated by the fact that it can only be cut and polished using diamond-tipped machines. However, while marble and granite may be more durable and attractive than concrete, marble and granite are relatively rare, thus making both marble and granite far too expensive to use on a wide-scale basis. Furthermore, marble and granite are hard to work with and cannot be delivered to a job site in a soft state.
It would therefore be desirable to provide a pigment paste and process for making the same that allows concrete to resemble natural stone, such as marble, granite, sandstone, bluestone, etc.